Police are keen to hear from three possible witnesses to the crash.
"One is the driver of a white car described as being close to the scene as the crash occurred.
"Police are also keen to speak with a truck driver wearing a hi-vis jacket who radioed his base for assistance and directed traffic prior to police arriving at the scene. Finally, we would like to speak to the driver of another car that was directly behind the first car on the crash scene," police said today.
Police believe the bus was travelling south towards Rotorua and failed to take a moderate bend.
As a result it went to the wrong side of the road, corrected and subsequently flipped.
Bishnal Basnet, who was travelling with his brother and uncle from Te Puke to Hamilton, was among the first people on the scene.
The crash site, he told the Herald last week, was chaos with people screaming and crying and trying to get off the bus in heavy rain.
He carried an Asian woman in her 50s on his back away from the bus before emergency services arrived 10 or 15 minutes later.
He stayed at the crash site directing traffic for about an hour.
Another witness said the bus windscreen was shattered and people were sitting down by the coach.
Survivors emerged from the crash site wrapped in blankets and being comforted by police officers.
Amanda Roberts arrived at the crash scene at the same time as the first fire engine and said she saw the white bus on its side in a ditch.
It did not appear otherwise damaged and there was no glass on the road.
Between six and eight people were outside the bus, including a couple who "didn't look too good", she said.
The stretch of State Highway 5 where the bus had crashed was winding and the bus had rolled while approaching a bend.
